CLLocationManager didEnterRegion: with iBeacon while app is suspended - ios

I'm trying to wake up my app (relaunch it) when it enters my defined beacon region but I just can't get it to work. This are the steps and code I'm using.
Set "Location updates" Background Mode to YES.
Monitor my CLBeaconRegion
NSUUID *uuid = [[NSUUID alloc] initWithUUIDString:#"EBEFD083-70A2-47C8-9837-E7B5634DF524"];
beaconRegion = [[CLBeaconRegion alloc] initWithProximityUUID:uuid identifier:#"daRegion"];
beaconRegion.notifyEntryStateOnDisplay = NO;
beaconRegion.notifyOnEntry = YES;
beaconRegion.notifyOnExit = YES;
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
[self.locationManager startMonitoringForRegion:beaconRegion];
Implement delegate methods
- (void)locationManager:(CLLocationManager *)manager didDetermineState:(CLRegionState)state forRegion:(CLRegion *)region;
- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region;
- (void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region;
Anything that I might be missing? I have read the documentation, blog posts, forums and nothing seems to work. This is one of the websites I read, and this is the other.

The comment "I just can't get it working when the app is killed" is critical.
If you use the iOS7 app switcher to kill an app (e.g. by swiping up on the app icon), then you will not be able to re-launch the app in the background upon entering or leaving an iBeacon region. This is by design -- if the user doesn't want the app running, then Apple thinks code should not be able to make it re-launch. See this thread.
Fortunately, users don't typically do this. For testing purposes, if you want to completely stop an app, don't do this. Reboot your phone instead. (Note, however, that it takes a minute or so after boot before you can detect iBeacons.)
EDIT 2014/03/10: This behavior has changed as of the release of iOS 7.1. Killing an app from the task switcher no longer stops it from detecting iBeacons in the background.

Related

iBeacon and iOS 9

I'm currently working on app that requires iBeacon monitoring.
I wrote the app one year ago, using iOS 8.x SDK.
It was working as it was supposed to, but now, one year from then, the same code doesn't work anymore (I'm testing it with the same beacons!).
Beacon regions detection has become much more unpredictable.
It has a will of its own.
Some beacons get detected, some are just ignored.
I couldn't find anything relevant on OpenRadar.
A few people complained about something similar on Apple Dev Forums, but Apple never came back to them.
Thoughts?
This is how I initialize the location manager.
self.locationManager = [CLLocationManager new];
self.locationManager.delegate = self;
// Worst accuracy is set in order to preserve battery life.
self.locationManager.desiredAccuracy = kCLLocationAccuracyThreeKilometers;
self.locationManager.allowsBackgroundLocationUpdates = YES;
// Required to keep the app living in the background.
// Background mode "Location Updates" is enabled.
[self.locationManager startUpdatingLocation];
I think before you were using geofences or CLCircular regions. Core location doesn't need any of that code to detect iBeacons. Try setting it up like this:
self.locationManager = [CLLocationManager new];
self.locationManager.delegate = self;
[self.locationManager startMonitoringForRegion:beaconRegion]; // Where "beaconRegion" is a CLBeaconRegion with a UUID that matches the beacon you want to detect (major & minor optional)
beaconRegion.notifyEntryStateOnDisplay = YES;
beaconRegion.notifyOnEntry = YES;
beaconRegion.notifyOnExit = YES;
You also need to add NSLocationAlwaysUsageDescription to your info.plist. Once all that is done, you should begin getting enter and exit events for your beacons through these two methods:
- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region;
- (void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region;

iOS stops finding beacons when locking the screen

I write an app that uses beacons and everything is working fine when the app is in the foreground. However when I press the power button and dim the screen the app is not finding any beacons anymore. The app is still hitting the:
- (void)locationManager:(CLLocationManager *)manager didRangeBeacons:(NSArray *)clBeacons inRegion:(CLBeaconRegion *)region
method, but the logger tells me what 0 beacons has been found, which is weird, because due to the documentation, this methods should be called only when there are any beacons in range:
Tells the delegate that one or more beacons are in range.
I already have kCLAuthorizationStatusAuthorizedAlways permission from user (it's added to .plist file as well) and I have added these capabilities to the project:
This is my code for ranging beacons:
- (instancetype)init {
self = [super init];
if (self) {
NSUUID *proximityUUID = [[NSUUID alloc] initWithUUIDString:[Registry environment].config.beaconUuid];
self.region = [[CLBeaconRegion alloc] initWithProximityUUID:proximityUUID identifier:proximityUUID.UUIDString];
self.locationManager = [CLLocationManager new];
self.locationManager.delegate = self;
}
return self;
}
- (void)stopMonitoringBeacons {
[self.locationManager stopMonitoringForRegion:self.region];
DDLogInfo(#"Stopped monitoring beacons.");
}
- (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region {
[manager requestStateForRegion:region];
[self startRangingBeacons];
}
- (void)startRangingBeacons {
[self.locationManager startRangingBeaconsInRegion:self.region];
DDLogInfo(#"Started ranging beacons.");
}
- (void)locationManager:(CLLocationManager *)manager rangingBeaconsDidFailForRegion:(CLBeaconRegion *)region withError:(NSError *)error {
DDLogInfo(#"Beacon ranging failed with error: %#.", error.localizedDescription);
}
- (void)locationManager:(CLLocationManager *)manager didRangeBeacons:(NSArray *)clBeacons inRegion:(CLBeaconRegion *)region {
DDLogDebug(#"Found %tu beacons.", clBeacons.count);
// call the server (no worries, not all the time)
}
Any idea what am I missing? Or maybe I can't trust these logs?
SOLVED:
The problem was the way I've tested it. As #davidgyoung mentioned, ranging works only in foreground and if we want to run it in background we need to start it from monitoring, which informs us about new beacons in background. I already did it in my code:
- (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region {
[manager requestStateForRegion:region];
[self startRangingBeacons];
}
But this method is called only if we meet new beacon. I was already simulating beacon when my app was in foreground, so when I dimmed the screen with power button, ranging was stopped and monitoring was never called - I would have to turn the beacon off/on or walk out/in of the beacon range to call this method again.
Beacon ranging on iOS generally only works in the foreground, and for about 10 seconds after your app first moves to the background. Beacon monitoring on the other hand can work in the background and wake your app up when a beacon is detected. If you do both ranging and monitoring simultaneously, you will again get 10 seconds of background ranging after a monitoring trigger wakes your app up in the background.
You can extend background ranging from 10 seconds to 3 minutes on request. I wrote a blog post on how to do this.

iBeacon monitoring not working properly

When there is a beacon in range of iOS device, I get notified(CLRegionStateInside) and can start ranging. This works properly. However, when ranging is started and the the iOS devices is not in range anymore, I don't get notified(State doesn't change to CLRegionStateOutside). Not in foreground or background.
Also didEnterRegion and didExitRegion never gets called. I start ranging in didDeterminState when state is CLRegionStateInside.
I do have background refresh settings enabled for my app.
When I start the app for the first time I do get an alert asking for location permission.
So basically, i'm able to start ranging, but i'm not able to stop ranging, because the state doesn't change to CLRegionStateOutside.
I use Xcode 6.3.1, iOS 8.3 on iPhone 4s.
This is my code:
INIT:
- (id)init{
self = [super init];
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
if ([self.locationManager respondsToSelector:#selector(requestAlwaysAuthorization)]) {
[self.locationManager requestAlwaysAuthorization]; //or requestWhenInUseAuthorization
}
NSUUID *uuid = [[NSUUID alloc] initWithUUIDString:#"B75FA2E9-3D02-480A-B05E-0C79DBB922AD"];
self.myBeaconRegion = [[CLBeaconRegion alloc] initWithProximityUUID:uuid
identifier:#"TESTREGIO"];
[self.locationManager startMonitoringForRegion:self.myBeaconRegion];
[self.locationManager requestStateForRegion:self.myBeaconRegion];
self.myBeaconRegion.notifyEntryStateOnDisplay = YES;
self.myBeaconRegion.notifyOnEntry = YES;
self.myBeaconRegion.notifyOnExit = YES;
return self;
}
DETERMINESTATE:
- (void)locationManager:(CLLocationManager *)manager didDetermineState:(CLRegionState)state forRegion:(CLRegion *)region {
if (state == CLRegionStateInside)
{
[self.locationManager startRangingBeaconsInRegion:self.myBeaconRegion];
}else{
[self.locationManager stopRangingBeaconsInRegion:self.myBeaconRegion];
}
}
DIDENTERREGION and DIDEXITREGION:
- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion*)region
{
NSLog(#"DidenterRegion================================================");
}
- (void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region {
NSLog(#"DidexitRegion================================================");
}
You are not going to get a didExitRegion notification unless you were already inside a region. I suggest you track the state of the region your are looking for separately.
I don't understand what you are doing in didDetermineState. You started ranging for your beacon in init(). You would not need to start ranging again.
A few tips:
You do not need to request any background permissions for this to work.
calls to didExitRegion happen 3 seconds after a beacon is no longer detected when the device is ranging in the foreground. In the background, or in the foreground when not ranging, these calls can be delayed for up to 15 minutes. These delays always exist on iPhone 4S models. On newer models, the delays may or may not exist depending on whether there are enough hardware assist slots for detecting beacons. See details here: http://developer.radiusnetworks.com/2014/03/12/ios7-1-background-detection-times.html
I suspect the failure to get exit events is really an issue of them taking longer than expected. Wait 15 minutes and see if the callbacks come.
You should also call the following function to start ranging
[self.locationManager startRangingBeaconsInRegion:self.myBeaconRegion];

Ranging Beacons only works when app running?

I am having difficulties getting this to work for when the app is not running. I have locationManager:didRangeBeacons:inRegion: implemented and it is called when the app is running in the foreground or background, however it doesn't seem to do anything when I quit the app and lock the screen. The location services icon goes away and I never know that I entered a beacon range. Should the LocalNotification still work?
I have Location updates and Uses Bluetooth LE accessories selected in Background Modes (XCode 5) I didn't think I needed them.
Any help greatly appreciated.
-(void)watchForEvents { // this is called from application:didFinishLaunchingWithOptions
id class = NSClassFromString(#"CLBeaconRegion");
if (!class) {
return;
}
CLBeaconRegion * rflBeacon = [[CLBeaconRegion alloc] initWithProximityUUID:kBeaconUUID identifier:kBeaconString];
rflBeacon.notifyOnEntry = YES;
rflBeacon.notifyOnExit = NO;
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
[self.locationManager startRangingBeaconsInRegion:rflBeacon];
[self.locationManager startMonitoringForRegion:rflBeacon];
}
-(void)locationManager:(CLLocationManager *)manager didRangeBeacons:(NSArray *)beacons inRegion:(CLBeaconRegion *)region {
if (beacons.count == 0 || eventRanged) { // breakpoint set here for testing
return;
}
eventRanged = YES;
if (backgroundMode) { // this is set in the EnterBackground/Foreground delegate calls
UILocalNotification *notification = [[UILocalNotification alloc] init];
notification.alertBody = [NSString stringWithFormat:#"Welcome to the %# event.",region.identifier];
notification.soundName = UILocalNotificationDefaultSoundName;
[[UIApplication sharedApplication] presentLocalNotificationNow:notification];
}
// normal processing here...
}
Monitoring can launch an app that isn't running. Ranging cannot.
The key to having monitoring launch your app is to set this poorly documented flag on your CLBeaconRegion: region.notifyEntryStateOnDisplay = YES;
This can launch your app on a region transition even after completely rebooting your phone. But there are a couple of caveats:
Your app launches into the background only for a few seconds. (Try adding NSLog statements to applicationDidEnterBackground and other methods in your AppDelegate to see what is going on.)
iOS can take its own sweet time to decide you entered a CLBeaconRegion. I have seen it take up to four minutes.
As far as ranging goes, even though you can't have ranging wake up your app, you can make your app do both monitoring and ranging simultaneously. If monitoring wakes up your app and puts it into the background for a few seconds, ranging callbacks start up immediately. This gives you a chance to do any quick ranging actions while your app is still running.
EDIT: Further investigation proves that notifyEntryStateOnDisplay has no effect on background monitoring, so the above should work regardless of whether you have this flag. See this detailed explanation and discussion of delays you may experience
Code for iOS 9 to range beacons in the background, by using Location Updates:
Open Project Settings -> Capabilities -> Background Modes -> Toggle Location Updates and Uses Bluetooth LE accessories to ON.
Create a CLLocationManager, request Always monitoring authorization (don't forget to add the Application does not run in background to NO and NSLocationAlwaysUsageDescription in the app's info.plist) and set the following properties:
locationManager!.delegate = self
locationManager!.pausesLocationUpdatesAutomatically = false
locationManager!.allowsBackgroundLocationUpdates = true
Start ranging for beacons and monitoring region:
locationManager!.startMonitoringForRegion(yourBeaconRegion)
locationManager!.startRangingBeaconsInRegion(yourBeaconRegion)
locationManager!.startUpdatingLocation()
// Optionally for notifications
UIApplication.sharedApplication().registerUserNotificationSettings(
UIUserNotificationSettings(forTypes: .Alert, categories: nil))
Implement the CLLocationManagerDelegate and in your didEnterRegion send both startRangingBeaconsInRegion() and startUpdatingLocation() messages (optionally send the notification as well) and set the stopRangingBeaconsInRegion() and stopUpdatingLocation() in didExitRegion
Be aware that this solution works but it is not recommended by Apple due to battery consumption and customer privacy!
More here: https://community.estimote.com/hc/en-us/articles/203914068-Is-it-possible-to-use-beacon-ranging-in-the-background-
Here is the process you need to follow to range in background:
For any CLBeaconRegion always keep monitoring on, in background or foreground and keep notifyEntryStateOnDisplay = YES
notifyEntryStateOnDisplay calls locationManager:didDetermineState:forRegion: in background, so implement this delegate call...
...like this:
- (void)locationManager:(CLLocationManager *)manager didDetermineState:(CLRegionState)state forRegion:(CLRegion *)region{
if (state == CLRegionStateInside) {
//Start Ranging
[manager startRangingBeaconsInRegion:region];
}
else{
//Stop Ranging
[manager stopRangingBeaconsInRegion:region];
}
}
I hope this helps.
You are doing two separate operations here - 'ranging' beacons and monitoring for a region. You can monitor for a region in the background, but not range beacons.
Therefore, your implementation of locationManager:didRangeBeacons:inRegion: won't get called in the background. Instead, your call to startMonitoringForRegion will result in one / some of the following methods being called:
– locationManager:didEnterRegion:
– locationManager:didExitRegion:
– locationManager:didDetermineState:forRegion:
These will get called in the background. You can at that point trigger a local notification, as in your original code.
Your app should currently wake up if you're just wanting to be notified when you enter a beacon region. The only background restriction I know of concerns actually hosting an iBeacon on an iOS device. In that case, the app would need to be physically open in the foreground. For that situation, you'd be better off just doing the straight CoreBluetooth CBPeripheralManager implementation. That way you'd have some advertising abilities in the background.

Region monitoring in iOS: didEnterRegion fires but didExitRegion does not in simuator

I am using CLLocationManager to monitor regions in iOS. I set up the delegate in the normal way:
self.locationManager = [[[CLLocationManager alloc] init] autorelease];
self.locationManager.delegate = self;
and implement several delegate functions including:
- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region
{
NSLog(#"GeoFence: didEnterRegion");
}
- (void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region
{
NSLog(#"GeoFence: didExitRegion");
}
Then I start monitoring a region with:
CLLocationCoordinate2D coordinates = CLLocationCoordinate2DMake(lat, lng);
CLRegion *grRegion = [[CLRegion alloc] initCircularRegionWithCenter:coordinates radius:radius identifier:[NSString stringWithFormat:#"grRegion%i", 1]];
CLLocationAccuracy acc = kCLLocationAccuracyNearestTenMeters;
[self.locationManager startMonitoringForRegion:grRegion desiredAccuracy:acc];
with appropriate values for lat (51.116261), lng (-0.85300) and radius (200). After building and running the app in the iPhone 5.1 simulator, I use the location injection tool in Xcode 4.3 to move between a distant location to my target location and back again. Under this procedure, the didEnterRegion event correctly triggers but the didExitRegion never does. I also receive other delegate callbacks such as didUpdateToLocation. I have varied the pattern of simulated movements, used the simulator's location setting tool rather than Xcode's, and tried the same tests running the app on an iPhone 4S with iOS 5.1. All tests have the same result.
I have ensured WiFi is enabled as suggested in other threads and looked through other questions on related topics in vain. Any suggestions as why one of the region transition events would fire, but not the other?
I had this same issue in 5.1. I filed a radar with Apple as a bug. It would trip the first event, in or out, but no other events after that.
From what I can see, this issue has been resolved in the iOS 6 beta. So look for it to be resolved when iOS 6 goes live.
Radar: 11715223

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